Electric heating device.



O. AALBURG.

ELECTRIC HEATING DEVICE,

APPLICATION FILED NOV.19,1908.

974,329. Patented Nov. 1, 1910.

T 1 My ATTORNEY device.

U ITED'sTATEs PATENT OFFICE.

CHRISTIAN AALBORG, or WILKINsnt-IRG, PENNSYLVANIA, ASSIGNOR, BY MEsim AS- sIeNMENrs-To WESTINGHOUSE nLEeTRIca MANUFACTURING COMPANY, or East PITTSBURG, PENNSYLVANIA, AcORPQRA'rIoN or PENNSYLVANIA.

- ELECT BICdI-I EA'IING DEVICE.

To all who'm it may concern: j v I Be it lknownjthat I, CHRISTIAN A LB RG, a citizen of the. United States, and a resident of Wilkinsburg, in the-county otAllegheny and State 'ot Pennsylvania, have invented a, new and useful Improvementin Electric Heating Devices, of which the following is a specification. My invention relates to electric heating apparatus,,and it has special reference to suchdevices as are adapted for heating water and other fluids as they pass through a tube or pipe comprising a part of the The object of my invention is to provide aniniproved fluid-heating device that shall be simple and durable in construction and in whicha maximum amount of the heat generated in the resistance elementshall be utilized in raising the temperature of the Electrical devices for heating water and other fluids andfor generating steam are usually so constructed that the resistance elements are operated at very high tempera tures relative to those of the tubes through which the fluid passes.

According to my present invention, I utilize a resistance elementcomprising a strip or ribbon of steel or other suitable conductingmaterial which is first wrapped with insulating material and is then disposed in the heating device under high pressure, as hereinafter pointed out.

The resistance element ispreterably insulated by mica or similar material which is not injured by high temperatures, and

is as thin as is consistent with the difference in voltage between the resistance element and the adjacent walls of the fluid-comluct- I sing tube.

Figure 1 of the accompanying drawings is an elevation and Fig. 2 is a detail view, partially in cross-section, of an electric heating device constructed in accordance with my invention.

Referring to the drawings, the device here illustrated comprises a tube or pipe 1 which is flattened into a substantially elliptical sec.- tion and is bent into the form of a zigzag grid, a plurality of. rods or bars 2 and 3 .wliich are located between the turns of the I Specification of Letters Patent. Application and November 19, 1908. seriai'ms'. 468,488;

Patented Novgl. 1910.

-zigzag grid and are held in position by clamping rods 4 and 5,

and resistance elements 6 and 7. n I

The outer ends of the rods l and 5 extend through holes or slots in end frames 8 and 9which areheld in position by clamping nuts 10; The inner ends of the rods 2 and 3 are rounded to tit-the bends in the zigzagtube, and their outer ends are no vided with holes 10 to receive the rods .4: and The resistance elements are first wrapped in an envelop 11 of insulating material and are, then disposed adjacent to the respective sides of the flattened tube, being held firmly in position by the rods 2 and 3 and the end plates 8 andl).

The ends of the tube are adapted to receive a pipe connection of any suitable kind so that water or other fluid may be caused to flow continuously through the zi zag grid. After the parts are assemblec as above indicated, the resistance element and its insulating envelop are subjected to high pressure by means oi the clamping bolts or rods i and 5 so that practically all the heat generated in the resistance is absorbed by the I water or other fluid traversing the tube. The resistance element is completely protected from mechanical injury and the as seinbled heater occupies a relatively small amount of space and is efiicient in operation. The pressure exerted on the resistance element and its insulating envelop is materially increased by reason of the pressure of the fluid within the flattened tube, the section of -which tends to assume a circular form.

The resistance strip or ribbon maybe of any suitable type, but I prefer to use one which is similar to that illustrated and described in Patent No. 890,856, granted June 16, 1908, to the I'Tadaway Electric Heating & Engiimering Company, upon an application filed by lVilliam S. Hadaway, J1.

It will, of course, be understood that the heater may be indefinitely extended and ma comprise a plurality of zigzag grids witi their fluid-conducting tubes connected in sei ries or multiple and with the resistance elements connected in any suitable manner. The terminals of the resistance elements may be arranged to suit the service conditions of the-device.

) Variations in the form of the flattened tube and of the clampin structure may-be -made within the scope o my invention.

zigzag grid of flattened fluid-containing tubing and resistance elements forced into engagement with the outer surfaces of the flattened tubing and insulated therefrom.

3. An electric heating device comprising a zigzag grid of flattened fluid-containing tubing, rods or bars disposed between the turns of the grid, relatively fiat resistance elements interposed between the adjacent surfaces of the rods or bars and of the .tubing and insulated therefrom, and means for compressing the zigzag grid from end to end. I 7

l.- -An electric heating device comprising a fort " flattened fluid-containing tube, an insulated resistance element in close contact with the fiat outer surface of the tube, and means for clamping said parts" together the tendency e tube to assume a circu ar section un der internal fluid pressure being partially relied upon to press the resistance element against the adjacent surface of the tube.

5. An electric heating device comprising a zi zag grid offlattened fluid-containing tu ing, rods or bars disposed between the turns of the grid, relatively flat resistance elements interposed between the adjacent surfaces of the rods or bars and of the tubing and insulated therefrom and a clam in frame composed of end pieces and si e be ts for compressing the zigzag grid from end to end.

In testimony whereof, I have hereunto subscribed my name this 16th day of November, 1908.

l CHRISTIAN AALBORG.

Witnesses; WM. Bnimsmw, BIRNEY HINES. 

